BS ISO 6101-1:2019 pdf free.Rubber- Determination of metal content by atomic absorption spectrometry.
8.2.1.1 Ash the test portion (8.1.1) in accordance with method A or method B of Iso 247-1, using the muffle furnace (±3L) maintained at 550 °C ± 25 °C. After ashing, allow the crucible and its content to cool to ambient temperature. If the ash is black, caused by a small amount of carbon black, add 1 cm3 of concentrated nitric acid (5S) to the ash, evaporate to dryness on an electrical heating plate or sand bath heated by a gas burner (6.12) and return to the muffle furnace and ash for 10 mm to 15 mm. 8.2.1.2 If the rubber contains halogenated compounds, carry out destruction of the organic matter in the test portion (8.1.2) in accordance with the following alternative procedure. Add to the test portion (8.1.2), 10 cm3 to 15 cm3 of sulfuric acid (5.JJ and heat moderately until the test portion has disintegrated. Carefully add S cm3of nitric acid (5.S). Continue heating until the test portion has completely decomposed and white fumes are evolved. Some rubber formulations cause considerable splashing; in this case, use a larger conical flask. 8.2.2 Dissolution of inorganic matter using hydrochloric acid 8.2.2.1 Add carefully 20 cm3 of 1 ÷ 2 hydrochloric acid (5.3.1) to the residue and heat for 30 mm on a steam bath (6.14). Cover with a watch glass (6.15) to avoid losses, for example due to carbonates, which cause splashing and foaming. Transfer the solution and the residue to a beaker (fA) with 50 cm3 of 1 + 2 hydrochloric acid solution (5.3.1) and heat for 30 mm. If the residue dissolves completely, transfer to 50 cm3 volumetric flask (ES), dilute to the mark with 1 + 2 hydrochloric acid solution (5.3.1), and proceed in accordance with 4.8.2.2.2 If the ash is not totally dissolved when following the procedure described in 8.2.2.1, repeat the ashing in accordance with 8.2.1.1 or 8.2.1.2 using a new test portion, and proceed as follows. Transfer the ash from the new test portion to a platinum crucible (6.9]. Add a few drops of sulfuric acid (5.1) and heat to fuming. Cool and add a further 3 drops of sulfuric acid (5.1) and 5 cm3 of hydrofluoric acid (5.4). Heat on the electric heating plate or sand bath (6.12) in a fume cupboard and evaporate to dryness, while stirring with the platinum rod [6.10]. Repeat this digestion with the same quantities of sulfuric and hydrofluoric acids twice. NOTE Borosilicate-glass rod is not suitable to stir samples digested with hydrofluoric acid.BS ISO 6101-1 pdf download.